Insomnia is a common problem, affecting over 95 million Americans. In addition to being a source of worry, physical discomfort, and moodiness, the estimated annual cost for the treatment of insomnia is $10.9 billion, costs of reduced productivity due to insomnia is $41 billion, and approximately 56,000 automobile accidents are cited as due to insomnia and fatigue each year. Cognitive-behavioral therapy (CBT) has been found to have significant short-term and long-term benefits as well as excellent patient acceptance. However, while it is often the treatment of choice, availability of CBT for insomnia is limited by many factors, including lack of trained clinicians, poor geographical distribution of knowledgeable professionals, expense, and inaccessibility to treatment and clinicians due to work schedules and competing commitments. This study will develop and evaluate the feasibility of a cost-effective, more accessible alternative treatment approach for insomnia. Traditional CBT, including the behavioral, cognitive, and educational aspects, will be operationalized and transformed for an Intemet intervention system, so individuals can access a personalized treatment any time, at their own convenience. Phase 1 of this study will involve developing the web program. Our research team has extensive experience developing such web interventions, as well as considerable experience with insomnia. Phase 2 will be a pilot test of the Internet intervention. Forty individuals with insomnia will be assessed pre and post the six week treatment program. It is hypothesized that the Internet intervention will promote improvements in sleep, mood, and cognitive functioning, while reducing costs associated with insomnia. Findings indicating feasibility will allow refinement and optimization of the Internet intervention, Phase 3, and creation of a potential future clinical trial.